Comparison study of executive functions in Parkinson's disease and degenerative cerebellar disease's patients

Objective: To compare executive functions (EF) in non-demented mild to moderate Parkinson's disease (PD) (Hoehn and Yahr <= 3) and pure degenerative cerebellar disease (CD) in order to evaluate the relative contribution and differential role of basal ganglia and cerebellum in those functions. Method: 14 patients with PD and 14 patients with CD matched by sex, education, disease's duration and MMSE were selected. A standardized neuropsychological battery and the Wisconsin Card Sorting Test (WCST) were administered. Z scores were compared for both groups through t-test for independent samples were used. Results: The cerebellar group showed significant lower performance in measures of attention and EF, with a significant increase in both perseverative and non perseverative errors during the WCST. On the other hand the PD group showed a selective increase of non perseverative errors, without reaching significant between group difference. Conclusion: The CD group appears to have greater deficits in EF with a pattern of prefrontal dysfunction.